diff --git a/backend/app/engine/generate.py b/backend/app/engine/generate.py
index 1581194..d591ce6 100644
--- a/backend/app/engine/generate.py
+++ b/backend/app/engine/generate.py
@@ -10,7 +10,7 @@ from app.engine.vectordb import get_vector_store
 from app.settings import init_settings
 from app.engine.retriever.CHBM25Retriever import CHBM25Retriever
 from llama_index.core.ingestion import IngestionPipeline
-from llama_index.core.node_parser import SentenceSplitter
+from llama_index.core.node_parser import SentenceSplitter,MarkdownNodeParser
 from llama_index.core.settings import Settings
 from llama_index.core.storage import StorageContext
 from llama_index.core.storage.docstore import SimpleDocumentStore
@@ -35,10 +35,11 @@ def get_doc_store(docType:str):
 def run_pipeline(docstore, vector_store, documents):
     pipeline = IngestionPipeline(
         transformations=[
-            SentenceSplitter(
-                chunk_size=Settings.chunk_size,
-                chunk_overlap=Settings.chunk_overlap,
-            ),
+            #SentenceSplitter(
+                #chunk_size=Settings.chunk_size,
+                #chunk_overlap=Settings.chunk_overlap,
+            #),
+            MarkdownNodeParser(),
             Settings.embed_model,
         ],
         docstore=docstore,
@@ -86,6 +87,7 @@ def generate_datasource():
 
         # Build the index and persist storage
         persist_storage(docstore, vector_store)
+        persist_BMRetriever(vector_store)
 
     logger.info("Finished generating the index")
 
diff --git a/backend/app/engine/retriever/HybridRetriever.py b/backend/app/engine/retriever/HybridRetriever.py
index 00b5495..be03e08 100644
--- a/backend/app/engine/retriever/HybridRetriever.py
+++ b/backend/app/engine/retriever/HybridRetriever.py
@@ -24,13 +24,13 @@ class HybridRetriever(BaseRetriever):
         self._vecRetriever = vector_index.as_retriever(
             similarity_top_k=similarity_top_k,filters = filters
         )
-
+        self._bm25Retriever = None
         STORAGE_DIR = os.getenv("BM_RETRIEVER_PATH", "storage_bm")
         if os.path.exists(STORAGE_DIR) and len(os.listdir(STORAGE_DIR)) > 0:
             self._bm25Retriever = CHBM25Retriever.from_persist_dir(STORAGE_DIR)
         else:
-            bmRetriver = CHBM25Retriever.from_defaults(similarity_top_k=similarity_top_k,nodes=self._vector_index.vector_store.get_nodes(None))
-            bmRetriver.persist(STORAGE_DIR)
+            self._bm25Retriever = CHBM25Retriever.from_defaults(similarity_top_k=similarity_top_k,nodes=self._vector_index.vector_store.get_nodes(None))
+            self._bm25Retriever.persist(STORAGE_DIR)
         self._alpha = alpha